Earthsky Interviews
Private: Salmon Flow
08-18-2004 - Earth
_DB:_ We wondered if these early stream flows – possibly related to global warming – were having an impact on wild salmon. We asked Thomas Quinn, a professor of Aquatic and Fishery Sciences at the University of Washington in Seattle. He told us that some salmon – like the West Coast chum – spend most of their lives in the Pacific Ocean. Others, like the more familiar Chinook and Coho salmon, spend more time inland along rivers and streams that empty into the Pacific.
_JB:_ Clearly, salmon more dependent on fresh water are more vulnerable to earlier stream flow. We also spoke with Chris Peery, Director of the University of Idaho Fish Ecology Research Lab. He said that, at this time, an even greater impact comes from dams and reservoirs in at least one river – the Columbia River in the Pacific Northwest. Dams and reservoirs even out the natural “pulses” of water that salmon depend on for migration cues. And they slow salmon down, making them more vulnerable to predators and disease.
_DB:_ So salmon are already facing challenges from human activities. Earlier river flows from a warming climate will only add to those challenges. Thanks today to the “U.S. Geological Survey”:http://www.usgs.gov/ and to the “National Fish and Wildlife Foundation”:http://www.nfwf.org/. We’re Block and Byrd for Earth and Sky.
Websites of interest about Atlantic Salmon:
“ICES reports on status of the stocks in the North Atlantic 2003 and draft 2004″:http://www.ices.dk/iceswork/wgdetailacfm.asp?wg=WGNAS (available to public soon) – these are fairly long technical documents in pdf. Older reports are available “here”:http://www.ices.dk/committe/acfm/wg/wgnas/wgnas.htm.
“NASCO “:http://www.nasco.int/ (North Atlantic Salmon Conservation Organization)
Reports mentioned are:
S O’Neil, J Ritter, K. Robichaud-LeBlanc (eds). 2000. Proceedings of a workshop on research strategies into causes of declining Atlantic salmon returns to North American Rivers. Sponsored by Fisheries & Oceans Canada Science Branch. Canadian Stock Assessment Secretariat Proceedings Series 2000/18
Cairns, D.K. 2001 An evaluation of the possible causes of the decline in pre-fishery abundance of North American Atlantic salmon. Canadian Technical Report of Fisheries & Aquatic Sciences No. 2358
Authors Notes:
According to Chris Peery, dams and reservoirs hamper salmon, like Chinook, via their manipulation of flow. Spring flows occur sooner as dams and reservoirs release water for power generation. Aa a result, there are fewer “pulses” of water, of which salmon depend on for migration cues. Furthermore, the salmon must negotiate the dams and reservoirs themselves, which causes higher straying rates and lower survival. Any further shift in flow, such as early shifts in flow due to temperature increases, would potentially add to the problem. An early pulse of water into dams and reservoirs cannot necessarily be stored or used.
The following people were interviewed for today’s program. Our thanks to:
Chris Peery
Assistant Research Professor
Director
Fish Ecology Research Laboratory
University of Idaho
Moscow, Idaho
Thomas P. Quinn
Professor
Aquatic and Fishery Sciences
University of Washington
Seattle, Washington
Joan G. Trial
Senior Biologist
Maine Atlantic Salmon Commission
Bangor, ME